1. Field of the Invention
The present invention relates to lifting devices, namely cranes. More particularly, the present invention relates to an improved knuckle boom king post crane apparatus that employs a rack and pinion mechanism to articulate one boom section relative to another boom section and a unique knuckle boom luffing arrangement.
2. General Background of the Invention
A knuckle boom crane is a hydraulically powered articulated arm that can be fitted to a support structure, usually a truck or trailer. The jointed sections of the boom can be folded into a small space when the crane is not in use.
Several articulated boom crane constructions have been patented. Examples of possibly relevant patents can be found below.
The following US patents for cranes listed in the table below are each incorporated herein by reference:
TABLEPATENTISSUE DATENO.TITLEmm/dd/yyyy4,105,151Crane Conversion MethodAug. 8, 19784,184,600Method for Removing a Bearing AssemblyJan. 22, 1980of a Pedestal Crane and a RemovableBearing Assembly for a Pedestal Crane4,216,870Crane MountingAug. 12, 19804,354,606Bearing Assembly for a Pedestal CraneOct. 19, 19824,513,869Pedestal Crane Mounting SystemApr. 30, 19854,602,462Boom Articulating Mechanism for AerialJul. 29, 1986Devices4,688,688Jib Crane Arrangement Having a RotatableAug. 25, 1987Mast4,828,125Device for Maintaining a Tool AttachmentMay 9, 1989in a Knuckle Boom Crane on a ConstantLevel Above the Ground5,328,040Thrust-Centering Crane and MethodJul. 12, 19945,487,478Inverted Kingpost CraneJan. 30, 19965,669,517Articulating Boom Incorporating a LinkageSep. 23, 1997Counterweight6,336,565Articulating Truss BoomJan. 8, 20026,672,467Articulating Truss BoomJan. 6, 2004